不要惹姐姐让你大姨妈倒流
[bù yào rĕ jiĕ jiĕ ràng nĭ dà yí mā dăo liú]
A humorous yet somewhat harsh way of saying “don’t provoke me”, literally translated as 'Don't mess with me or I will make your period go backwards', using hyperbole to threaten punishment for disrespecting them.